[Mesa-dev] [PATCH v2 23/36] isl: Remove duplicate px->sa conversions

[Nanley Chery]

On Fri, Jul 01, 2016 at 04:08:49PM -0700, Jason Ekstrand wrote:
> In all three cases, we start with width and height taken from
> isl_surf::phys_slice0_extent_sa which is already in samples.  There is no
> need to do the conversion and doing so gives us an incorrect value.

Thanks for noticing this bug! I think this patch is missing one
necessary change. The level width and height must be adjusted
for the sample count.

Here's an example that demonstrates the post-patch issue:
 * User creates a 2x1px 4xIMS image
 * Level 0 is 4x2sa (2x1px) 
 * Level 1 is 2x1sa (1x1px) but should be 2x2sa

- Nanley

> ---
>  src/intel/isl/isl.c | 20 --------------------
>  1 file changed, 20 deletions(-)
> 
> diff --git a/src/intel/isl/isl.c b/src/intel/isl/isl.c
> index 404cfc1..be3adfc 100644
> --- a/src/intel/isl/isl.c
> +++ b/src/intel/isl/isl.c
> @@ -610,18 +610,6 @@ isl_calc_phys_slice0_extent_sa_gen4_2d(
>        uint32_t W = isl_minify(W0, l);
>        uint32_t H = isl_minify(H0, l);
>  
> -      if (msaa_layout == ISL_MSAA_LAYOUT_INTERLEAVED) {
> -         /* From the Broadwell PRM >> Volume 5: Memory Views >> Computing Mip Level
> -          * Sizes (p133):
> -          *
> -          *    If the surface is multisampled and it is a depth or stencil
> -          *    surface or Multisampled Surface StorageFormat in
> -          *    SURFACE_STATE is MSFMT_DEPTH_STENCIL, W_L and H_L must be
> -          *    adjusted as follows before proceeding: [...]
> -          */
> -         isl_msaa_interleaved_scale_px_to_sa(info->samples, &W, &H);
> -      }
> -
>        uint32_t w = isl_align_npot(W, image_align_sa->w);
>        uint32_t h = isl_align_npot(H, image_align_sa->h);
>  
> @@ -1285,17 +1273,9 @@ get_image_offset_sa_gen4_2d(const struct isl_surf *surf,
>     for (uint32_t l = 0; l < level; ++l) {
>        if (l == 1) {
>           uint32_t W = isl_minify(W0, l);
> -
> -         if (surf->msaa_layout == ISL_MSAA_LAYOUT_INTERLEAVED)
> -            isl_msaa_interleaved_scale_px_to_sa(surf->samples, &W, NULL);
> -
>           x += isl_align_npot(W, image_align_sa.w);
>        } else {
>           uint32_t H = isl_minify(H0, l);
> -
> -         if (surf->msaa_layout == ISL_MSAA_LAYOUT_INTERLEAVED)
> -            isl_msaa_interleaved_scale_px_to_sa(surf->samples, NULL, &H);
> -
>           y += isl_align_npot(H, image_align_sa.h);
>        }
>     }
> -- 
> 2.5.0.400.gff86faf
> 
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